K-wire and method for surgical procedures

ABSTRACT

A surgical guide wire or K-wire and method of use are provided. The K-wire or guide wire has opposite end portions and a shank portion in between. One end portion has a deformable end portion that, once outside of a confining guide passage, can be deformed to present a projected forward facing area that is larger than the transverse cross section of the K-wire or guide wire while in the passage. The increased area will provide increased resistance to additional forward axial movement into the surgical site.

CROSS REFERENCE TO RELATED APPLICATION

In accordance with 37 C.F.R 1.76, a claim of priority is included in anApplication Data Sheet filed concurrently herewith. Accordingly, under35 U.S.C. §119(e), 120, 121, and/or 365(c), the present invention claimspriority as a continuation of U.S. Non-Provisional Utility applicationSer. No. 13/974,747, filed Aug. 23, 2013, entitled, “K-WIRE AND METHODFOR SURGICAL PROCEDURES, which is a continuation-in-part to U.S.Non-Provisional Utility application Ser. No. 13/722,641, filed Dec. 20,2012, entitled, “K-WIRE AND METHOD FOR SURGICAL PROCEDURES”, now issuedU.S. Pat. No. 8,540,747, which issued on Sep. 24, 2013, which is acontinuation-in-part to U.S. Non-Provisional Utility application Ser.No. 12/823,791, filed Jun. 25, 2010, entitled, “K-WIRE AND METHOD FORSURGICAL PROCEDURES”, now issued U.S. Pat. No. 8,361,102, which issuedon Jan. 29, 2013, which claims priority to U.S. Provisional PatentApplication No. 61/220,828, filed Jun. 26, 2009, entitled, “K-WIRE ANDMETHOD FOR SURGICAL PROCEDURES”. The contents of each of the abovereferenced applications are herein incorporated by reference in itsentirety.

FIELD OF INVENTION

The present invention relates to an improved guide wire or K-wire foruse in surgical procedures such as orthopedic procedures, and inparticular, spinal procedures such as percutaneous pedicle screwconstructs.

BACKGROUND OF THE INVENTION

In certain surgical procedures, a K-wire (Kirschner wire) or guide wireis used in combination with a surgical tool such as a jamshidi needle.The jamshidi needle is used to form a hole through bone as a first stepin certain medical procedures like attaching a screw to a pedicle. TheK-wire or guide wire is inserted through the needle into the interior ofthe bone, which, if not done properly, can injure the patient,particularly if it engages certain sensitive parts which may includebreaching the anterior cortex of a vertebral body. The K-wire or guidewire is used as a portal for certain surgical steps like guiding a tap,screw or screwdriver to the surgical site. The procedures oftentimesrequire the use of force which can cause a properly positioned K-wire orguide wire to move forward into the surgical site, which, if excessive,can move into contact where contact is to be avoided.

A K-wire or guide wire is generally cylindrical and has a diameter ofabout 3 millimeters, making it easy to move during use. In fact, theK-wire or guide wire is designed to move during its installation;however, once installed its movement is not impeded, requiring care inits use. The cross sectional size of the K-wire though is limited by thetools and devices it is used with. Each tool or device is provided witha through bore for receiving the K-wire or guide wire, limiting the sizeand type of wire that can be used. Additionally, the K-wire is typicallyremoved by passing through a through bore in a device or tool. Thus, todate, only K-wires with a small diameter, generally cylindrical roundcross section, have been used which presents the problem in their use.It should also be noted that while the K-wires or guide wiresillustrated herein include a solid center core, the K-wire or guide wiremay be a hollow tubular member without departing from the scope of theinvention.

The present invention provides a solution to this problem by providingan improved K-wire or guide wire which, when inserted, providesincreased resistance to forward axial movement while still being usablewith traditional surgical tools and devices.

DESCRIPTION OF THE PRIOR ART

U.S. Pat. No. 5,431,651 discloses a cross pin and set screw femoral andtibial fixation device for mounting a ligament graft. The deviceincludes a drill guide for drilling a transverse hole. The drill guideis releasable from a first twist drill so as to leave it in place. Thefirst twist drill is used to guide further drilling and passage of afastener device. A K-wire or the first twist drill is used for guiding asecond twist drill for enlarging the transverse hole and for guiding andturning a cannulated fastener device into a femoral bone end of theligament graft. There is no feature on the K-wire to limit the extent ofits insertion subsequent to it passing through the bone.

U.S. Pat. No. 7,575,578 discloses a surgical drill guide including ahandle and an arm having an end which contacts a bone. The handleincludes a plurality of slots or channels which receive a sleeve. Thesleeve is used to guide a K-wire into the bone. The K-wire serves as aguide for drilling a tunnel into the bone. The K-wire does not include afeature to limit the extent of its insertion subsequent to it passingthrough the bone.

U.S. Published Patent Application No. 2007/0239159 discloses devices anda system for placing bone stabilization components in an individual. Inparticular, the bone stabilization components are placed on the spine.Various tools, including a K-wire, are employed to properly locate,place and secure the devices in an individual.

U.S. Published Patent Application No. 2007/0270896 discloses a devicefor accessing the pedicle of a vertebra including a Jamshidi needle.

SUMMARY

The present invention involves the provision of a K-wire which can beused with traditional surgical tools and devices. The inventive guidewire or K-wire has an end portion that, upon exit from the through boreof a surgical tool or device, can be changed in a controlled manner topresent a deformable end portion that will provide a forward face with alarger projected area than the end surface of the K-wire while in thethrough bore. The deformation may be induced mechanically from internalstress, thermally or otherwise.

The present invention also involves the provision of a method ofconducting surgery utilizing a guide wire or K-wire. The method includespassing a guide wire or K-wire through a tool or device into a surgicalslit with the guide wire or K-wire presenting a forward facing area of afirst size. The guide wire or K-wire then has an end portion moved outof the tool or device where the forward end portion can be expanded topresent a forward facing area of a second size larger than the firstsize. After use, the guide wire or K-wire may be extracted from thesurgical site through a surgical tool or device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of vertebra showing a jamshidi needleextending through a pedicle;

FIGS. 2A, 2B are side elevation views of a K-wire or guide wire showingtwo configurations of one end portion of the K-wire or guide wire;

FIG. 3 is an enlarged fragmentary view of a K-wire or guide wire showingan end portion shown configured to present an expanded forward face;

FIG. 4 is a fragmentary side sectional view of a jamshidi needle with aK-wire or guide wire in a through bore;

FIGS. 5A and 5B are enlarged fragmentary side views of an end portion ofa K-wire or guide wire with one embodiment of reformable end portion;

FIGS. 6A and 6B are enlarged side views of an end portion, expanded andunexpanded, of a further embodiment of a K-wire or guide wire of thepresent invention;

FIG. 7 is an enlarged side view of an end portion of a still furtherembodiment of a K-wire or guide wire of the present invention;

FIG. 8 is an enlarged side view of an end portion of a still furtherembodiment of a K-wire or guide wire of an end portion of the presentinvention;

FIG. 9 is an enlarged side view of an end portion of an embodiment ofthe invention similar to that shown in FIG. 2B;

FIG. 10 is an enlarged side view of an end portion of a still furtherembodiment of the present invention;

FIG. 11 is an enlarged side view of the embodiment illustrated in FIG.10 with the end portions spread apart;

FIG. 12 is an enlarged side view of a still further embodiment of thepresent invention;

FIG. 13 is an enlarged side view of a still further embodiment of thepresent invention; and

FIG. 14 is a view of the present invention used in a surgical procedure.

Like numbers used throughout the Figures designate like or similar partsand/or construction.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describedpresently preferred embodiments with the understanding that the presentdisclosure is to be considered an exemplification of the invention andis not intended to limit the invention to the specific embodimentsillustrated.

Referring generally to the figures, the reference numeral 10 designatesgenerally a K-wire or guide wire usable in surgical procedures incombination with a surgical tool such as a jamshidi needle 12, drill ortap (not shown), or a surgical device such as a screw, plate or implant.K-wires (also called Kirschner wires) or guide wires are well known inthe art. Jamshidi needles are also well known in the art and have ashank 14 with a through bore 16 (as would a drill, tap or screw) and asharpened distal end 17. A handle 18 may also be provided at theproximal end 20 of the shank 14 for facilitating insertion of the shankinto a surgical site 21, such as a vertebra 22 with a pedicle 23 in apatient such as a human. A surgeon may manipulate the jamshidi needle 12using the handle 18, and may also apply impact force to the shank 14 bystriking the handle with a hand or impact tool such as a hammer.Jamshidi needles are used to penetrate bone in the performance of asurgical procedure such as attaching a screw 24 to bone. A rod (notshown) may be installed in the through bore 16 during hole formation toincrease rigidity of the shank 14. The rod is removed to provide athrough bore 16 for the K-wire 10 insertion. After forming a hole 25with the jamshidi needle 12, the K-wire or guide wire 10 is insertedinto the interior of the bone and the jamshidi needle is removed,leaving the K-wire or guide wire in place. In some surgical procedures,like spinal surgery, the K-wire or guide wire is inserted through onewall of a bone, e.g., a pedicle 23 and is placed against an oppositebone wall. If care is not taken during surgery, the K-wire or guide wiremay be pushed through the opposing bone wall creating a risk of injury.The present invention is a solution to this potential problem.

The K-wire or guide wire 10 is typically used as a pilot or guide forother surgical tools or devices such as drills, taps, plates, implantsand screws. In the attachment of a screw 24 (FIG. 5B), the screw canhave a through bore 44 that receives the K-wire or guide wire forguiding the screw to a drilled and tapped hole 25. After installation ofthe screw 24, the K-wire or guide wire 10 is then extracted through thethrough bore 44 of the screw 24 by simply pulling on the K-wire or guidewire to reduce the frontal area of the K-wire or guide wiresubstantially to its original size.

The K-wire or guide wire 10 has opposite end portions 26, 28 and agenerally cylindrical intermediate portion 30 positioned between the endportions. The length of the K-wire or guide wire 10 is preferably longenough to extend beyond both ends of the surgical tool being used, e.g.,a jamshidi needle 12. The K-wire or guide wire 10 is sized and shaped tobe freely movable along the through bore 16. The end portion 28 will bereferred to as the manipulative end and the end portion 26 will bereferred to as the operative end for convenience. Preferably, the entirelength of the manipulative end portion 28 and the intermediate portion30 is generally cylindrical to facilitate removal of a tool or devicefrom an installed K-wire or guide wire 10.

The operative end portion 26 is provided with a section 32 that iscontrollably deformable. The section 32 may be an integral portion ofthe K-wire or guide wire 10 or attached thereto. Several differentsections 32 are described below. In general, the section 32 isconfigurable to fit within the through bore 16 and freely movabletherein. It is insertable into the through bore 16 for insertion intothe surgical site 21 for use and for removal from a through bore in thetool or device. The K-wire or guide wire may also be removed prior to alater surgical step if it is no longer needed. For example, if theK-wire or guide wire is not needed to guide the screw 24 for insertion,it may be removed prior to attaching the screw 24. When outside of thethrough bore 16, the operative end 26 expands automatically or can bemanually expanded to present an expanded face with a projected areagreater than the transverse cross sectional area of the K-wire or guidewire 10 while positioned in the through bore 16. By way of example, theoperative end 26 seen in FIG. 3 has a projected area of approximately(given that the end 33 of the bend at the intermediate section 30 ofK-wire or guide wire 10 is rounded reducing the area slightly) L times Wwhereas the K-wire or guide wire has a cross sectional area of A=πr²where r is equal to W/2. It is preferred that the reconfigured crosssectional projected area be at least about 1.5 times, and preferably atleast about twice the size of the first cross sectional area of theK-wire or guide wire as described below.

The K-wire or guide wire 10 or the deformable portion of the K-wire orguide wire may be made of a deformable material which will allow atleast the operative end 26 to be configured between first and secondconfigurations (see FIGS. 2A and 2B) with one configuration (FIG. 2B)presenting a larger projected area than the first (FIG. 2A) as discussedabove. One suitable reconfigurable material is referred to as a shapememory alloy such as Nitinol. A reversible, solid phase transformationknown as martensitic transformation is the force behind shape memoryalloys. Such alloys are well known and form a crystal structure which iscapable of undergoing a change from one form of crystal structure toanother. Temperature change and/or loading can initiate the shapetransformation. By way of example, above its transformation temperature,Nitinol is superelastic, able to withstand deformation when a load isapplied and return to its original shape when the load is removed. Belowits transformation temperature, it displays the shape memory effect.When it is deformed below its transformation temperature, it will remainin that shape until heated above its transformation temperature, atwhich time it will return to its original shape. The original shapewould then be the bent form and then it can be reformed cold tostraight. Upon heating, the bend will return. The heat (or temperatureincrease) can be provided by contact with the patient. Elasticallydeformable materials may also be used, such as spring steel with highyield strength, where stress is induced to change a shape is elasticallyreleased to change the shape of the deformed member back to its nonstressed shape. An embodiment of the invention, shown in FIGS. 5A and 5Band described below, could be made using a spring material. Plasticallydeformable materials might also be used for some operative end portion26 configurations. The terms resiliently deformable, plasticallydeformable and spring are used generally to indicate a material propertywhen the material is deformed during typical use of the K-wire or guidewire as described herein. Controlled bending can be induced by usingcontrolled weak points such as a groove or the like at selectedstrategic locations. The embodiment in FIGS. 5A and 5B might also beused with a plastically deformable material. The screw 24 or other toolor device that is anticipated to be the last one used with the K-wire orguide wire 10 may be provided with a forcing cone 35 to help reconfigurethe end portion 26 back to its unexpanded shape to conform it to fitwithin a passage like passages 16, 44 for insertion or removal. Anembodiment of this form is seen in FIGS. 5A and 5B and is describedbelow.

In the embodiment shown in FIGS. 1-3, the operative end 26 has alaterally extending portion 36 when out of the through bore 16. Thedeformation to lateral extension may be provided as described above byapplying heat to effect bending from memory. The portion 36 may beprovided as a permanent bend in the K-wire or guide wire 10 which canthen be deformed to straight by confinement in the through bore 16, andupon exit from the through bore will reassume its bent configuration.The material properties of the end portion 26 may be selected to providefor straightening of the bend for removal through a passage or borewhich may be facilitated, e.g., by the use of a forcing cone 35. Thelateral extension presents a larger projected area to further limitforward axial motion into the surgical site.

FIG. 4 shows a surgical tool configuration that can be used tofacilitate directing a K-wire or guide wire 10 out of the through bore16. It uses a curved tip 37 to direct the exiting K-wire or guide wire10.

In the embodiment shown in FIGS. 5A and 5B, the operative end 26 is inthe form of an expandable cage 40 having a plurality of rods 42 that canassume an extended position; FIG. 5A illustrates a contractedconfiguration of cage 40 when in a through bore 16 of shank 14. FIG. 5Billustrates the cage 40 in its expanded configuration and a screwpositioned on the K-wire or guide wire 10. The embodiment of FIGS. 5Aand 5B may be constructed in at least two ways, resiliently deformablerods 42 or plastically deformable rods 42. A memory metal alloy may beused. A polymeric material such as PEEK may also be used for at leastthe rods 42. If the rods 42 are elastically deformable, they can beformed as biased to an outward or expanded configuration, where onceoutside of the through bore 16 they will move outwardly to relieveinduced stress to provide the expanded configuration like in FIG. 5B.The rods 42 may also be plastically deformable, and upon application ofaxial force will move to an expanded position as in FIG. 5B. When theK-wire or guide wire is in the through bore 16, the rods 42 assume orare in the collapsed configuration and when the rods 42 are outside ofthe bore, they assume or are forced into the expanded position providingan increased projected area for engagement with material in the surgicalsite as discussed above. It is to be noted that the rods may also bemade of a memory alloy as described above. The forcing cone 35 may beused to facilitate removal of the K-wire or guide wire 10 through thethrough bore 44. The distal ends of the rods 42 may be held in placewith an end cap 43. The projected area of the end portion 26 whenexpanded, as seen in FIG. 5B, would be that area defined or bounded byoutermost extending portions of the rods 42 as at portions 46.

FIGS. 6A and 6B illustrate another embodiment of the invention. FIG. 6Ashows an end portion 26 with an expandable end bulb 50 that may be madeout of a memory alloy that, upon heating, assumes the expandedconfiguration illustrated in FIG. 6B. This embodiment is particularlyadapted for use when extraction of the K-wire or guide wire is otherthan through a tool or device passage.

FIG. 7 illustrates another embodiment of the invention. It utilizes apair of opposed legs 61, 62. The legs 61, 62 are constructed to move inan outward direction either from spring action or from otherwisereassuming a formed shape as from a temperature change as by using amemory alloy as described above. In the illustrated embodiment, the legs61, 62 have overlying portions at 63.

FIG. 8 illustrates an additional embodiment of the invention and issimilar to the form shown in FIG. 7 by having two legs 71, 72, but thelegs do not overlap; rather the legs diverge from a common area 73 andhave a gap 74 therebetween when in the extended position as shown.

The embodiments of the invention shown in FIGS. 6-8 all utilize a shank14 of one material and an end portion of another material such as aspring material or a memory alloy.

FIG. 9 illustrates a still further embodiment of the present invention.It is similar to the K-wire or guide wire 10 shown in FIG. 2 and has ashank 14 with an attached end portion 26 having a single extending leg80 shown in its extended configuration. The portion 80 may be providedas a permanent bend in the K-wire or guide wire 10 which can then bedeformed to straight by confinement in the through bore 16, and uponexit from the passage will reassume its bent configuration. The materialproperties of the end portion 80 may be selected to provide forstraightening of the bend for removal through a passage which may befacilitated, e.g., by the use of a forcing cone. The lateral extensionpresents a larger projected area to further limit forward axial motioninto the surgical site.

FIGS. 10 and 11 illustrate a still further embodiment of the presentinvention. The end portion 26 of the K-wire or guide wire includes aplurality of deformable ends, illustrated herein as independent legs 82and 84. The K-wire or guide wire of FIGS. 10 and 11 can be made from ashape memory alloy such as Nitinol. Other shape memory alloys andmaterials can also be used. The ends 82 and 84 are normally deformedoutwardly from the longitudinal axis 85 of the K-wire or guide wire at acommon area diverging point 87 as shown in FIG. 11 within the guidewire. As such, the deformable ends, or legs 82 and 84 form separatestructures which can move outwardly, independent of each other from thecommon area diverging point 87. The legs 82 and 84 are separated by agap 87 which runs the length of the legs 82 and 84 and is orientated ina generally parallel manner from the longitudinal axis 85 of the guidewire 10. The deflection of the ends 82 and 84 presents a larger endsurface area when the K-wire or guide wire is penetrating a bone. Thislarger end surface offers more resistance and consequently prevents theK-wire or guide wire from penetrating too far into the bone and perhapspassing into an adjacent bone or outside of the intended bone. Thelength of the ends 82 and 84 together with the different shape memoryalloys determine how quickly the ends 82 and 84 deform outwardly afterthey enter a bone. The more rapidly they deform, the less they penetrateinto a bone. The ends 82 and 84 collapse together, as shown in FIG. 10,when the K-wire or guide wire is withdrawn back through the Jamshidineedle. A groove 86 on end 82 permits projection 88 to fit therein whenin the collapsed position.

As further illustrated, the K-wire or guide wire 10 is shown with one ofthe deformable ends being longer than the opposing deformable end. Asillustrated, leg 82 is longer than leg 84. Leg 82 includes a tip portion89 that extends past and is bent inwardly towards the leg 84 to overlapa tip portion 91 of the shorter leg 84. While most of the leg 82 isorientated in a generally parallel manner relative to the leg 84, atleast a segment of, if not all of the tip portion 89 is positioned in aperpendicular orientation relative to the leg 84. A second gap 93separates the tip portions 89 and 91. The second gap 93 therefore isformed substantially perpendicular to the longitudinal axis 85 when legs82 and 84 are in the non-deployed or not separated state.

FIGS. 12 and 13 illustrate other embodiments of the present invention.These embodiments are variations of the embodiment illustrated in FIGS.10 and 11. In FIG. 12 the end 82 of the K-wire or guide wire bendsoutwardly at 90. Also end 84 bends outwardly at 92. The bends 90 and 92are positioned within the legs 82 and 84 at some distance away from thecommon area diverging point 87, i.e. towards the tip portions 89 and 91.This embodiment permits the ends 82 and 84 to bend outwardly from thelongitudinal axis more rapidly than the embodiments of FIGS. 10 and 11.In FIG. 13, the end 82 bends outwardly at 94 and the end 84 bendsoutwardly at 96. Bends 94 and 96 are closer to the tip portions 89 and91. Thus, they permit the ends 82 and 84 to bend outwardly from thelongitudinal axis more rapidly than the bends 90 and 92 of FIG. 12. Thefaster the ends move away from the longitudinal axis, the less theK-wire or guide wire penetrates into the bone. Therefore, the embodimentof FIG. 13 would penetrate less into a bone than the embodiment of FIG.12. Also the embodiment of FIG. 12 would penetrate less into a bone thanthe embodiment of FIGS. 10 and 11.

The present invention also includes a method of conducting a medicalprocedure using a K-wire or guide wire, as illustrated in FIG. 14. Asurgeon or other medical personnel places a surgical tool end at thesurgical site. The initial surgical tool used preferably has a guidingthrough bore opening at the distal tool end such as that described abovefor a jamshidi needle 12. A K-wire or guide wire 10 is guided to thesite by passing the K-wire or guide wire through the through bore 16until the operative end 26 extends beyond the open end of the throughbore 16. A funnel 98 helps the surgeon place the K-wire or guide wireinto the Jamshidi needle. The operative end 26 of the K-wire has atleast a portion deformed after its exit from the through bore 16 suchthat the deformed portion presents a projected area greater than thecross sectional area of the K-wire or guide wire when in the throughbore 16 as described above. The deformation can occur automatically asby increasing the temperature of the operative end portion 26 when itincludes a memory metal alloy. The deformation may also be induced byrelieving stress induced into the operative end portion as when thedeformable portion is constructed of a spring material. The deformationmay also be induced mechanically by the application of an axiallydirected force along the K-wire or guide wire 10. After at least aportion of the surgery, the K-wire or guide wire can be removed asdescribed above. The K-wire or guide wire is used to guide surgicaltools and/or devices to the surgical site during the surgical procedure.Once the K-wire or guide wire has been inserted into the bone, thejamshidi needle can be withdrawn and a cannulated tap or otherinstrument can be slid down the K-wire or guide wire and inserted intothe bone. When the tap reaches the expanded ends 82, 84 of the K-wire itwill stop its forward progress. Thus, this invention avoids the need forfluoroscopy to determine the position of the tap or other instrument ina bone.

It is to be understood that while certain forms of the invention areillustrated, it is not to be limited to the specific forms orarrangements herein described and shown.

It will be apparent to those skilled in the art that various changes maybe made without departing from the scope of the invention and theinvention is not to be considered limited to what is shown and describedin the specification and any drawings/figures included herein.

One skilled in the art will readily appreciate that the presentinvention is well adapted to carry out the objectives and obtain theends and advantages mentioned, as well as those inherent therein. Theembodiments, methods, procedures and techniques described herein arepresently representative of the preferred embodiments, are intended tobe exemplary and are not intended as limitations on the scope. Changestherein and other uses will occur to those skilled in the art which areencompassed within the spirit of the invention and are defined by thescope of the appended claims. Although the invention has been describedin connection with specific preferred embodiments, it should beunderstood that the invention as claimed should not be unduly limited tosuch specific embodiments. Indeed, various modifications of thedescribed modes for carrying out the invention which are obvious tothose skilled in the art are intended to be within the scope of thefollowing claims.

What is claimed is:
 1. A method of conducting a medical procedure using a guide wire, the method including: placing a surgical tool end at a surgical site, said surgical tool having a guiding through bore opening at the tool end; guiding a guide wire to the site by passing the guide wire through the passage, said guide wire having an operative end portion; and deforming a portion of the operative end portion after its exit from the passage such that the deformed portion presents a projected area greater than the cross sectional area of the guide wire when in the passage.
 2. The method of claim 1 wherein the deforming occurs automatically.
 3. The method of claim 1 wherein the deforming is induced by increasing the temperature of the operative end portion.
 4. The method of claim 1 wherein the operative end portion has a deformable portion constructed of memory metal alloy.
 5. The method of claim 1 wherein the deforming is induced by relieving stress induced into the operative end portion when in the guiding passage.
 6. The method of claim 1 wherein the operative end portion has a deformable portion constructed of a spring material.
 7. A method of conducting a medical procedure using a K-wire, the method including: placing a surgical tool end at a surgical site, said surgical tool having a guiding through bore opening at the tool end; guiding a K-wire to the site by passing the K-wire through the passage, said K-wire having an operative end portion; and deforming a portion of the operative end portion after its exit from the passage such that the deformed portion presents a projected area greater than the cross sectional area of the K-wire when in the passage. 